Vehicle elevator

ABSTRACT

A storage system (10), preferably for vehicles comprising a plurality of storage bays (11) each having an opening, at least one moving device (15) movable to be adjacent the opening of any one of the storage bays (11) and transfer device (90, 20) for transferring objects (21) carried by the moving devices (15) into the storage bay (11). Preferably the storage bays (11) are arranged in two arrays and the moving devices (15) is capable of transferring an object to a storage bay (11) in either array.

TECHNICAL FIELD

This invention relates to storage systems having a plurality of storagebays for storing articles. More particularly it relates to a systemuseful in storing vehicles.

BACKGROUND ART

In urban areas it is common to provide multilevel car parking buildings.The buildings have multiple floors connected by ramps. One drives avehicle from floor to floor until a free parking bay is found. Such carparks have a low usage of floor space due to the need for roadways andthe requirement that each parking bay be sufficiently large to allow avehicle to be driven into the bay and for the driver and any passengersto exit the vehicle.

It has been proposed to replace access ramps with a vertical lift toeach floor. However it is still necessary to provide roadways on eachfloor and large size parking bays. It has also been proposed to uselifts which not only have a platform which can be moved vertically toaccess parking bays on different levels but which also have a transportdevice which moves the vertical lift horizontally to access laterallyadjoining parking bays.

DISCLOSURE OF THE INVENTION

The present invention provides in one of its aspects a Lifting transferdevice for use in a storage system having a plurality of first storagebays, each storage bay having an access opening through which an objectmay be inserted into or removed from the storage bay, said accessopenings arranged in a first common surface, the device comprising:

transport means restrained to move in a horizontal plane and in adirection parallel to the common surface;

lift means mounted on the transport means and restrained to movevertically relative to the transport means and in a direction parallelto the common surface; and

transfer means mounted on the lift means characterised by having:

a first wheeled trolley for receiving and supporting an object thereon,said first wheeled trolley supported on the lift means and movablethereon from a position distant from the storage bay to a position nextto or partially in the storage bay, and drive means having first andsecond modes of operation, said first mode of operation causing saidfirst wheeled trolley to move relative to the lift means and said secondmode of operation for driving the object from the wheeled trolley intothe storage bay or from the storage bay onto the wheeled trolley whilstthe first wheeled trolley is prevented from moving relative to the liftmeans.

Preferably the object comprises a second wheeled trolley adapted to besupported on the first wheeled trolley and adapted to support a wheeledvehicle.

In a second aspect of the present invention there is provided a storagesystem comprising a first plurality of storage bays, each storage bayhaving an access opening through which an object may be inserted into orremoved from the storage bay, said access openings arranged in a firstcommon surface, and a lifting transfer device of the abovementionedkind.

Preferably the storage bays are arranged with their openings arranged onat least one vertical surface.

More preferably the vertical surface is planar.

Preferably the transport means is movable run along a horizontallyextending track.

Preferably the lift means is cantilevered from the main frame of thetransport means and extends transversely of the vertical face.

More preferably the main frame comprises two spaced apart paralleluprights and the lift means comprises a sub-frame having two spacedapart parallel L-shaped support members, each depending from arespective upright.

More preferably the uprights comprise I beams and the support membersinclude guide wheels which run in the channels of the I beams.

Preferably the storage bays are arranged in two stacks with the openingsof the stacks opposing and at least one lifting transfer device locatedintermediate the opposing openings.

Preferably the or each lifting transfer device is capable of moving anobject to any bay in both stacks. Even more preferably there areprovided two lifting transfer devices located intermediate the opposingopenings, each of which may access any bay in both stacks.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood from the following descriptionof a preferred but non-limiting embodiment which is provided withreference to the drawings in which:

FIG. 1 is a schematic perspective view of an embodiment of theinvention;

FIG. 2a is a schematic plan view of the embodiment of FIG. 1;

FIG. 2b is a schematic side view of the embodiment of FIG. 1;

FIG. 3 is a side view of an embodiment of the invention showing hiddendetail and with the transfer plate and pallet not shown;

FIG. 4 is an expanded view of part of FIG. 3;

FIG. 5 is a partial end cross-sectional view through the sub-frame ofthe embodiment of FIG. 3;

FIG. 6 is a schematic view of a pallet according to the invention;

FIGS. 7 and 7a show details of the drive mechanisms of the embodiments;and

FIG. 8 shows details of an alternative drive mechanism.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to FIGS. 1, 2a and 2b there is provided a storage structure 10having a plurality of storage bays 11. The bays 11 are arranged in rowsand columns and each have an opening on a vertical front face 12.

The bays 11 may be constructed of concrete or steel girders or any othersuitable material with or without floors, walls or ceilings. Mountedadjacent the front face 12 is a lifting mechanism 15. The liftingmechanism 15 comprises a main frame 16 extending the height of thecolumns of bays 11 and a sub-frame 17 mounted on the main frame 16. Themain frame 16 is supported by wheels 18 and is movable horizontallyacross the front face 12 upon a track 19 while the sub-frame 17 ismovable vertically relative to the main frame. The movement of the twoframes may be achieved by any of a number of conventional means, such asa rack and pinion system or hydraulic rams. By appropriate movement ofthe main frame 16 and sub-frame 17 it is possible to position thesub-frame 17 adjacent any selected storage bay 11.

The sub-frame 17 supports a wheeled pallet 20 which in turn supports anarticle 21 to be stored. When the sub-frame 17 is positioned adjacentthe relevant bay 11, a transfer mechanism (not shown) transfers thepallet 20 and its article 21 into the bay 11, or vice versa. Once anarticle 21 has been placed in a bay, the lifting mechanism 15 mayretrieve or place another article from or into another storage bay.

The main frame 16 of the lifting mechanism comprises a pair of spacedapart vertical column members 22 while the sub-frame 17 comprises twospaced apart horizontal arms 23 extending away from the front face 12.The column members 22 are horizontally braced so as to remain parallel.Such bracing is not shown in the drawings.

As shown in FIGS. 2a and 2b a second set of storage bays 10b may beplaced adjacent the free end 24 of the sub-frame 17 and, with a suitabletransfer mechanism capable of transferring a pallet 20 from both stacksof bays, a single lift 15 may service both stacks. It is furtherpossible to provide a second lifting mechanism which runs along thefront face of the second stack. The spacing between the two opposingfront faces 12a, 12b must be increased such that the free end of onesub-frame can pass the main frame of the other lift. Such an arrangementallows for continued operation should one of the lifts requiremaintenance or repairs, since the other lift can access all bays on bothstacks without hindrance from the other lift. It will be appreciatedthat in a two lift arrangement a gap must exist between the free end ofeach sub-frame and the front face adjacent to that free end. Thus bynecessity the transfer mechanism must be capable of transferring apallet off the free end of the sub-frame over the gap and into thestorage bay without failure or jamming. Further if, as will be normal,there exists a gap between the front face and the inside end of thesub-frame, then the gap at the free end will be greater than this gap atthe inner end.

By horizontal movement of the main frame 16 any one of the columns ofstorage bays may be accessed. By vertical movement of the sub-frame 17any one of the rows of storage bays may be accessed. Thus by appropriatemovement of the main frame 16 and sub-frame 17, the sub-frame 17 may bepositioned adjacent any storage bay.

Referring to FIGS. 3 and 4, the stacks of bays along which the liftingmechanism 15 runs is provided with a lower guideway on the ground. Thelower guide track is a U-shaped channel in which runs lower guide wheels31 attached to the main frame via a mounting 32. Each vertical columnmember 22 is preferably provided with a lower guide wheel 32. An upperguide way 33 is provided adjacent the second level and comprises an Ibeam having the channels 34 of the I facing upwards and downwards. As analternative, the I beam may be replaced with two C-sections arrangedwith their bases abutting and their channels facing upwards anddownwards. In fact, how the channels are provided is unimportant. Twosets of two upper guide wheels 35 depending from the two column members22 of the main frame 16 via mountings 36 run in the two channels 34 ofthe I beam 33. Preferably the upper and lower guide wheels 31, 35 areflanged to limit movement into the appropriate channel 30, 34.

Mounted on the external vertical face of the lower guideway 30 is ahorizontally extending toothed track 40. A similar toothed track 41 ismounted on the external face of the upper guideway 33. The main frame 16rotatably supports a vertical shaft 42 having toothed cogs 43 at eachend which engage the upper and lower toothed tracks 40, 41. A motor 44is provided to rotate shaft 42 and hence cogs 43. By rotation of theshaft 42, the cogs 43 drive the lifting mechanism 15 horizontally alongthe side of the stacks. The shaft 42 and cogs 43 act to maintain thecolumn members 22 vertical, since both the upper and lower ends areconstrained by the rack and pinion arrangement to move together.Although the mainframe 16 may be provided with only one shaft 42(although two may be used), due to the bracing between the two uprightmembers 22, both members 22 are maintained in a vertical position.

There is provided a horizontal track 50 extending parallel to the frontsurface 12 upon which the main frame 16 runs. Preferably this track ismounted on the ground but it could be mounted on the stacks aboveground. Each column 22 of the main frame 16 is provided with at leastone pair of opposed flanged wheels 51. The wheels 51 run on the uppersurface of the track while their flanges are adjacent the side edges ofthe track, thus restraining the wheels to run along the track.

The two column members 22 of the main frame are preferably eachcomprised of an I beam. The sub-frame 17 is comprised of the twohorizontally extending arms 23, each opposite one of the I beams 22, avertical leg 55 and a bracing member 56. The sub-frame 17 has two setsof guide wheels 57, 58 mounted upon each of the vertical legs 55. It ispreferable that the two sets of each leg be spaced as far apart aspractical. Thus the upper set of guide wheels 57 is adjacent the freeend 60 of the leg 55 while the lower set 58 is adjacent the junction ofthe leg 55 and arm 23. Preferably each set comprises two guide wheels61. The guide wheels are mounted in the outwardly facing channels of theI beams 22 and run along the flanges of the beams.

In the embodiment shown there is provided a hydraulic ram 69 in orbeside one of the arms 22 of the sub-frame 17 having a first pulley 70mounted on the free end of the piston rod 71. An idler pulley 72 ismounted near the junction of the leg 55 and arm 73 and a cable 73, whichis attached at or near the top of the main frame 16, passes under theidler pulley 72, around the first pulley 70 and is then secured to thesub-frame 17. Contraction of the hydraulic ram 69 thus causes thesub-frame 17 to rise. It will be appreciated that two rams, each in oradjacent each arm, may be used.

Whilst a rack and pinion system is used to move the main frame 16 and ahydraulic ram/cable system is used for the sub-frame 17 it will beappreciated that other drive systems may be used for each use.

Referring to FIG. 5, the construction of the sub-frame 17 is shown inmore detail.

The two horizontally extending arms 23 are joined together on theirbottom surfaces by transverse beams 80. An angle 81 extending parallelto each arm 23 is provided on the inner face of the arm resting upon thetransverse beams 80. Preferably this angle 81 is welded or brazed to thearm and beams. The angle has a vertical leg 82 on its inner edge andcarries a first running track 83.

A wheeled transfer plate 90 is provided which has wheels 91, 97 mountedon its side edges to run along the first running tracks. Preferably thetransfer plate 90 has horizontally extending square hollow section beams92, parallel to the arms 23, from which the wheels 91, 97 extend. Thewheels 91 are mounted about horizontal axes and engage the horizontalsurface of the running track 83. The wheels 97 are mounted on verticalaxes and engage the vertical surface of the running tracks 83. Thus thetransfer plate is constrained to run parallel with the running tracks 83and is prevented from sideways movement. Mounted upon the top surface 93of each of the beams 92 is a second running track 94. A wheeled pallet20 is provided having wheels 98, 101 on its side edges. As with thetransfer plate, the wheels 98 rotate about horizontal axes and engagethe horizontal surfaces of the second running track 94 and the wheels101 rotate about vertical axes to engage the vertical surfaces of thesecond running tracks 94. The two running tracks 94 thus restrain thewheels 98 from sideways movement off the transfer plate 90. It will beappreciated that the horizontally and vertically mounted wheels of thetransfer plate and pallet may be replaced by linear bearings.

The upper surface 99 of the pallet 20 is provided with upstanding sideedges 100 such that an article placed on the upper surface 99 isconstrained between the side edges 100. Where the article is a wheeledvehicle the upstanding side edges 100 prevent the vehicle being drivenoff the side of the pallet 20 when placing the vehicle on the pallet 20.

Although not shown, the transfer plate 90 may be provided with acentrally located guide channel into which a guide member extending fromthe lower side of the pallet engages. The guide channel serves to locatethe pallet correctly relative to the transfer plate and in particularensures that the pallet wheels run on the tracks. Preferably at the endsof the guide track the sides expand outwards in a bell shape so thepallet may engage the guide member even when slightly miss-aligned. Thesides of the guide track may be undercut so as to prevent the guidemember disengaging by vertical movement.

As will be apparent from FIG. 4 the inner end of the sub-frame 17adjacent the front faces 12 of the bays 11 ends some distance from thefront face 12. Similarly with a two-stack system having two liftingmechanisms, the free end of the sub-frame is distant from the otherfront face. Thus it is not possible to transfer the pallet directly fromthe lift mechanism to the bay unless the relevant gap is closed. This isthe purpose of the transfer plate 90.

The lift mechanism 16 is positioned so that the second running tracks 94on the transfer plate 90 are aligned with the storage bay's floor orrunning surface. The transfer plate 90 is rolled along the first runningtracks 83 until it abuts against the end of the bay, thus forming acontinuous horizontal surface upon which the pallet's wheels 98 mayroll. The pallet 20 is then driven by a drive mechanism from thetransfer plate 90 onto the storage bay floor or running surface. Asshown in FIG. 5 the drive mechanism 110 may comprise a linear toothedtrack 111 on the underside of the pallet and a rotatable cog 112 drivenby a suitable motor (not shown) on the transfer plate 90. However otherdrive mechanisms, such as a chain having an arm which engages acomplementary arm or recess on the pallet 20 may be used. However thedrive mechanism must be capable of driving the pallet off both ends ofthe support frame and also retrieving a pallet in a storage bay anddriving it onto the transfer plate. In this regard the drive mechanismmay extend into the storage bay to engage a pallet stored therein.

Referring to FIGS. 7 and 7a, there is shown a mechanism for driving themainframe, sub-frame and in particular there is shown the transfermechanism 130.

The transfer mechanism 130 includes first and second pulley wheels 131,132 rotatably mounted on and above the top surface of the transfer plate90. The first pulley 131 is mounted near the inner end of the transferplate 90 while the second pulley 132 is mounted near the free end 24.

A first flexible member 134, preferably a chain, is wrapped around thepulleys 131, 132 such that rotation of the pulleys causes circulation ofthe flexible member 134. It will be appreciated that when the flexiblemember is a chain the "pulleys" will be toothed cogs. It is to beunderstood that in the following description of the transfer mechanismthe word "pulley" is to also mean "cog". Mounted on the flexible member134 at regular intervals are pairs of drive arms 135. Where the flexiblemember is a chain, each arm 135 of each pair is mounted on a separatelink of the chain so the pairs of arms abut. However the arms 135 arenot fixed together, such that the chain may rotate about each pulley.Alternatively, only one arm may be provided rather than pairs. A singlearm can be mounted on both pins of a single link.

The two pulleys 131, 132 may be mounted in the centre of the transferplate 90, as shown, or may be mounted at one side of the transfer plate.The pallet 20 has an inwardly extending arm 136 at each end whichextends to be adjacent the flexible member 134 such that the drive arms135 may engage them.

Rotation of the pulley wheels 131, 132 will cause the drive arms 135 toengage the pallet's arm 136 and drive the pallet 20 towards the right,as viewed in FIG. 7. Similarly, a counter clockwise rotation will drivethe pallet 20 towards the left. It will be appreciated that the pallet20 may be driven in either direction so that it is substantially off thetransfer plate 90, as shown in the detail in FIG. 7a.

As mentioned previously it is necessary for the transfer plate 90 tomove relative to the sub-frame 17. Accordingly, third and fourth pulleywheels 138, 139 are provided which are rotatably linked to the first andsecond pulley wheels 131, 132 respectively. In the embodiment shown, thethird and fourth pulley wheels 138, 139 are mounted coaxial with thefirst and second pulley wheels 131, 132 on common axles. However, ifdesired a gear arrangement may be utilised.

The third and fourth pulley wheels 138, 139 may be mounted above the topsurface of the transfer plate 90 or the axle may extend through thetransfer plate 90 and the pulleys 138, 139 may be mounted below thelower surface. However, their positioning is relatively unimportant.

A second flexible member 140, again preferably a chain, is wrappedaround the third and fourth pulley wheels 138, 139 around idler pulleys142 and hence around a drive pulley 143 driven by a suitable motor 144.The flexible member 140 also engages a brake pulley 146 which isconnected to a first brake mechanism 148, preferably a disc brake.

The transfer plate 90 is also preferably provided with a longitudinallyextending rack 149 which engages a pinion 150. The pinion is connectedto a second brake mechanism 151, again preferably a disk brake.Preferably, the disk brakes are mechanically operated by a doublehydraulic ram 152 such that when one brake is engaged the other isdisengaged and vice versa. The brake mechanisms 148, 151 of both diskbrakes are secured to the sub-frame 17.

The second brake 151 acts to prevent movement of the transfer plate 90when engaged. When the second brake 151 is engaged and the first brake148 disengaged, rotation of the motor 144 merely causes the first andsecond flexible members 134, 140 to circulate and to drive the pallet 20off in the appropriate direction while the transfer plate 90 remainsstationary.

When the first brake 140 is engaged and the second brake 151 released,the transfer plate 90 is free to move relative to the sub-frame 17 andthe second flexible member 140 is fixed relative to the brake pulley146.

If the motor 144 is now driven to cause an anticlockwise rotation of thedrive pulley 143, the length of flexible member 140 between the brakepulley 146 and the drive pulley 143 is reduced. The drive pulley 143 ismounted on the transfer plate 90 and the brake pulley 146 is mounted onthe sub-frame 17 and so the transfer plate 90 is urged towards the left.Simultaneously to this movement, the first and second pulleys 131, 132are caused to rotate in an anticlockwise direction, since they are fixedrelative to the drive pulley 143. Accordingly, the pallet 20 is driventowards the left relative to the transfer plate 90. Once the transferplate 90 has been driven sufficiently to the left, to span the gapbetween the storage bays 11 and the free end 24 of the sub-frame 17, thehydraulic ram 152 may be cycled to engage the second brake 151 and todisengage the first brake 148, thereby locking the transfer plate 90relative to the sub-frame 17. The pallet 20 may then be driven off thetransfer plate 90 by continued rotation of the motor 144 to be supportedonly by the storage bay's floor.

Once the pallet 20 is in the storage bay 11 the ram 152 is cycled toagain engage the first brake 148 and the motor 144 is then driven in aclockwise direction, thereby urging the transfer plate 90 towards theright. It will be appreciated that if there is a sufficient spacingbetween the drive arms 135 on the first flexible member 134, thetransfer plate 90 will have retracted a sufficient distance such thatthe driven arm 136 of the pallet 20 is not engaged by a drive arm 135 asit rounds the second pulley 132.

To retrieve the pallet 20 the cycle is reversed to firstly drive thetransfer plate 90 to adjacent the appropriate bay 11. Then the pallet 20is retrieved onto the transfer plate 90 and finally both pallet 20 andtransfer plate 90 moved to lie fully on the sub-frame 17. It will beappreciated that by driving the motor 144 in the opposite direction andby appropriate sequencing that a pallet 20 may be deposited andretrieved into and from a storage bay on the right hand side (inner end)of the sub-frame 17. It will also be appreciated that where the gaps atthe end of the sub-frame 17 are different, the movement of the transferplate 90 must also be different. However, it will be appreciated that,when extended, the transfer plate 90 abuts against the outer edge of thestorage bay 11, so merely driving the pallet 20 off the transfer plate90 will position it correctly relative to the storage bay 11--no precisecontrol in driving the pallet off the transfer plate is necessary.

FIG. 7 also shows an arrangement to ensure that both sides of thesub-frame 17 rise up the column members 22 equally when only a singlelift ram 69 is used. The equalising arrangement comprises a first pulley160 mounted on one side of the sub-frame 17 and a second pulley 131mounted on the other side. A flexible member 162 such as a wire, cableor chain is provided which is attached at one end to the top of one ofthe upright column members and at the other end to the bottom of theother upright column member 22. The flexible member 162 is passedunderneath the first pulley 160 and over the second pulley 161.Preferably, an idler pulley 163 is provided such that the flexiblemember 162 engages the second pulley 161 over 180°. If the sub-frame 17attempts to tip such that one side is higher than the other, theeffective length of the path to be followed by the flexible member 162will be greater than when both sides are at the same height. Thus byhaving a taut flexible member, such tipping is prevented.

Referring to FIG. 8 there is shown an alternative drive mechanism forthe transfer plate 90 and pallet 20.

The transfer plate 90 has two pulleys 210 and 211 mounted at either endon its upper surface. The flexible member 134 passes around the twopulleys 210, 211 and around a third pulley 212. This pulley 212 ismounted on the transfer plate 90 and operatively connected to pulley 212is a further pulley 213 and a brake mechanism 214. A second flexiblemember 215 is wrapped around the pulley 213, idler pulleys 216 and adrive pulley 217, driven by a motor 218. The idler pulleys 216, drivepulley 217 and motor 218 are mounted on the sub-frame 17. The two idlerpulleys 223 are mounted on the transfer plate 90.

The sub-frame 17 is provided with a rack 220 which engages with a pinionand brake mechanism 221 on the transfer plate 90. The two brakemechanisms 214, 221 are connected to opposite ends of a bar 222, pivotedabout a vertical axis at its centre 223 on the transfer plate 90. Oneend of the bar is connected to the piston end of a hydraulic orpneumatic ram 225. The other end of the ram is connected to a push-pullcable 226. The push-pull cable 226 is in turn connected via a pivotinglever arm mechanism 230 to two first safety lock members 231. Thehydraulic ram 225 is mounted on the transfer plate 90 but is free tomove along its length. The two first safety lock members 231 and thelever arm mechanism 230 are mounted on the sub-frame 17.

The two safety lock members 231 each have a cut out 232 adapted toreceive a second safety lock member 234 mounted on the top surface ofeach parking bay floor.

The two brake mechanisms 214, 221 are spring biased against the pivotingbar 222. When the safety lock members 231 are disengaged, retraction orextension of the hydraulic ram 225 will merely cause movement of thefirst safety lock members 231. However when the first and second safetylocks 231, 234 are engaged together, backwards or forwards motion of thelocking members 231, 234 is prevented. Thus extension or retraction ofthe ram 225 will cause a pivoting of the bar 222. The two brakemechanisms 214, 221 are arranged such that both are never releasedtogether. When one is disengaged the other is engaged, and vice versa.Preferably when changing states both are engaged.

In use the sub-frame 17 is raised just above the desired bay and the ram225 is actuated to extend the first lock members 231. The sub-frame 17is lowered so the lock members 231 engage the respective lock members234. The ram 225 is then extended to pivot bar 222 clockwise, as viewedfrom above and release brake mechanism 221. The motor 218 is then drivento rotate the flexible member 215 clockwise. Because the first brakemechanism 214 is still engaged the pulley 213 cannot rotate. Thus thetransfer plate 90 is driven towards the right. Because the pulley 212and hence flexible member 134 is prevented from rotating, the pallet 20does not move relative to the transfer plate 90. Once the transfer plate90 has been driven to its desired position, the motor 218 is stopped andthe ram 225 is retracted, thereby disengaging the first brake mechanism214 and engaging the second mechanism 221. The transfer plate 90 is thusprevented from moving relative to the sub-frame 17. The motor 218 isthen driven to rotate the flexible member 215 clockwise which in turnrotates the pulley 212 and the flexible member 134 clockwise, therebydriving the pallet 20 off the transfer plate 90 towards the right andonto the parking bay floor.

Referring to FIG. 6 there is shown a novel pallet 120 for use in avehicle storage system. The pallet 120 has two vehicle supportingrunways 121 extending longitudinally. Each runway 121 is supported atits ends by rollers or wheels (not shown) upon trackways 122 such thattransverse movement is possible. The two runways 121 are connectedtogether by a parallelogram linkage 123 which engages a centrallylocated rod 124. The linkage members 125 may slide along the rod 124such that sideways movement of one runway 121 causes a correspondingmovement relative to rod of the other runway 121 in the oppositedirection. The entry/exit end 126 of each runway 121 is provided withdiverging guides 127 such that when a vehicle is driven towards thepallet, if not correctly aligned, its wheels will contact the sides ofthe guides causing the runways to move into alignment with the correctwheel spacing. Thus instead of requiring a solid floor to accommodateall sizes of vehicles, with their varying wheel spacing, only the tworelatively narrow wheel runways are required, thus saving substantiallyon weight.

As mentioned earlier, conventional storage systems having a stationarylift have a fixed single entry/exit point. Thus persons entering aparking station must await in their vehicles until the entry/exit pointis free. However the lifting mechanism of the present invention mayaccess any "storage bay". Thus it is possible to provide the parkingstation with a number of bays which act as a buffer from which thelifting mechanism may take vehicles to be stored. A buffer of, forinstance, three bays, in which vehicles could be temporarily left, wouldallow persons to leave their vehicle when the lifting mechanism isoccupied without the need to wait. Similarly when a vehicle isretrieved, the lifting mechanism may retrieve another vehicle and placeit in a vacant entry/exit bay even if a first entry/exit bay is stilloccupied. Furthermore the entry and exit points may be at differentlocations. Thus for example the entry point, and any buffer, may be onthe lowest level while the exit point, and any buffer, may be at thehighest level.

It will be apparent to those skilled in the art that many obviousmodifications and variations may be made to the embodiments describedherein without departing from the spirit or scope of the invention.

We claim:
 1. A storage system, comprising:a plurality of first storagebays having at least two levels, each first storage bay having an accessopening through which an object may be inserted or removed, and theaccess openings of the first storage bays are arranged in a first commonsurface; a plurality of second storage bays having at least two levels,each second storage bay having an access opening through which an objectmay be inserted into or removed from the storage bay, and the accessopenings of the second storage bays are arranged in a second commonsurface parallel to the first; the first and second common surfaces arespaced apart from each other; a first lifting transfer device movablevertically and horizontally and located adjacent the first commonsurface and extending to a location proximate to the second commonsurface including means for inserting an object into or removing anobject from any of the first and second storage bays; a second liftingtransfer device, identical to the first lifting transfer device, movablevertically and horizontally and located adjacent to the second commonsurface and extending to a location proximate to the first commonsurface including means for inserting an object into or removing anobject from any of the first and second storage bays; the arrangementbeing such that the first and second lifting transfer devices are ableto travel horizontally along their respective common surfaces and areable to pass either above or below each other without colliding.
 2. Astorage system, according to claim 1, wherein each lifting transferdevice comprises:transport means restrained to move in a horizontalplane and in a direction parallel to the common surface; lift meansmounted on the transport means and restrained to move verticallyrelative to the transport means and in a direction parallel to thecommon surface; and transfer means mounted on the lift means and movableperpendicular to the common surfaces to insert or remove an object.
 3. Astorage system, according to claim 2, wherein the transfer means of eachlifting transfer device comprises:a first wheeled trolley for receivingand supporting an object thereon, said first wheeled trolley supportedon the lift means and movable thereon from a position distant from thestorage bay to a position next to or partially in the storage bay, anddrive means having first and second modes of operation, said first modeof operation causing said first wheeled trolley to move relative to thelift means and said second mode of operation for driving the object fromthe wheeled trolley into the storage bay or from the storage bay ontothe wheeled trolley whilst the first wheeled trolley is prevented frommoving relative to the lift means.
 4. A storage system, according toclaim 3, wherein in the first mode of operation the drive meanssimultaneously drives the object relative to the first wheeled trolley.5. A storage system, according to claim 4, wherein the first wheeledtrolley is provided with two spaced apart second running tracksextending substantially parallel with respect to one another and withrespect to lateral edges of the first wheeled trolley, and wherein asecond wheeled trolley is provided with a plurality of support wheelsmounted such as to run in the second running tracks, constrain thesecond wheeled trolley to run parallel with the second running tracksand substantially prevent lateral movement thereof on the first wheeledtrolley.
 6. A storage system, according to claim 4, wherein the firstwheeled trolley is provided with guide means which cooperate with aguide member of the second wheeled trolley to locate the lattercorrectly relative to the first wheeled trolley.
 7. A storage system,according to claim 6, wherein said cooperation of the guide means andthe guide member automatically locate the second wheeled trolley at acorrect position relative to the first wheeled trolley.
 8. A storagesystem, according to claim 3, wherein the object comprises a secondwheeled trolley retrievably supportable on the first wheeled trolley andadapted to carry a wheeled vehicle.
 9. A storage system, according toclaim 3, wherein the first wheeled trolley comprises two vehiclesupporting runways extending parallel with respect to one another andsupported such as to allow variable spacing in-between them, the runwaysbeing connected together by a linkage arm mechanism adapted to allowequidistant movement of the runways relative to a central axis extendingbetween them, and the runways being provided with guides adapted tocooperate with the wheels of a vehicle such as to cause the runways tomove into alignment with the wheel spacing of the vehicles.
 10. Astorage system, according to claim 9, wherein said cooperation of theguides with the wheels cause the runways to automatically align with thewheel spacing of the vehicle.
 11. A storage system, according to claim2, wherein the lift means comprises two horizontally extending parallelarms respectively guided on a corresponding one of two verticallyextending columns of a main frame of the transport means, the arms eachhaving first running track extending parallel with the arms, and whereina plurality of support wheels is mounted on the lateral edges of thefirst wheeled trolley to engage with the first running tracks, thewheels being mounted on the first wheeled trolley with their axis ofrotation such that the first wheeled trolley is contained to runparallel with the first running tracks and is substantially preventedfrom lateral movement thereon.
 12. A storage system, according to claim11, wherein the plurality of wheels on the first trolley, the secondtrolley or both trolleys are replaced by linear bearings.
 13. A storagesystem, according to claim 2, wherein the transport means of the firstlifting transfer device is mounted on a first track adjacent to thefirst common surface and the lift means extends transversely away fromthe first common surface.
 14. A storage system, according to claim 2,wherein the lift means of the first and second lifting transfer devicesend short of the second and first common surfaces, respectively, suchthat when the first and second lifting transfer devices are oppositeeach other, the lift means of the first lifting transfer device do notinterfere with the transport means of the second lifting transferdevice.
 15. A storage system, according to claim 2, wherein thetransport means of the first lifting transfer device is mounted on afirst track adjacent to the first common surface and the transport meansof the second lifting transfer device is mounted on a second trackadjacent to the second common surface and the first and the secondtracks are disposed at a common level orthogonal to the first and thesecond common surfaces.
 16. A storage system, according to claim 1,wherein said first lifting transfer device is supported only fromstructural members associated with the plurality of first storage baysand the second lifting transfer device is supported only from structuralmembers associated with the plurality of second storage bays.